Authentication can be implemented via a variety of methods including those that utilize the following: symmetric keys, asymmetric keys, hashing, or a check sum value. Authentication can be used to identify a user, a device, to facilitate payment, or for a variety of other purposes. Some example technologies that are used in conjunction with an authentication regime are: Radio-frequency identification (RFID), BLUETOOTH™, and 802.11(a-n) (collectively known as “WiFi”). An authentication regime, as implemented by these technologies, includes the providing of one of the aforementioned keys from a first device to second device, the second device authenticating the first device based upon the providing of the correct key.